One vertex per element, one color per generator, with an edge from x to x·s.
(9,10)(11,16)(12,13)(14,18)(15,19)(17,22)(20,23)(21,24)(25,26,30,34)(27,29,33,31)(28,36,38,32)(35,39,40,37)(1,2)(3,8)(4,6)(5,7)(11,19)(15,16)(20,24)(21,23)(25,27)(26,31)(28,35)(29,34)(30,33)(32,39)(36,37)(38,40) involution — undirected(1,3,5,6)(2,4,7,8)(9,11)(10,15)(12,20)(13,21)(14,19)(16,18)(17,23)(22,24)(25,26)(27,31)(28,32)(29,33)(30,34)(35,39)(36,38)(37,40)(1,2)(3,4)(5,7)(6,8)(9,11)(10,16)(12,20)(13,23)(14,19)(15,18)(17,21)(22,24)(25,26)(27,29)(28,32)(30,34)(31,33)(35,37)(36,38)(39,40) involution — undirected(9,12)(10,17)(11,20)(13,18)(14,22)(15,23)(16,21)(19,24)(25,28,30,38)(26,32,34,36)(27,35,33,40)(29,37,31,39)(1,4)(2,6)(3,7)(5,8)(9,13,14,17)(10,12,18,22)(11,21,19,23)(15,20,16,24)(25,29)(26,33)(27,34)(28,37)(30,31)(32,40)(35,36)(38,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.