One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,8)(3,6,4,7)(9,10)(11,12)(13,16)(14,17)(15,19)(18,20)(21,22)(23,24)(25,26)(27,34)(28,29)(30,32)(31,33)(35,39)(36,37)(38,40)(1,2)(3,6)(4,7)(5,8)(9,11,14,15)(10,12,17,19)(13,18,22,23)(16,20,21,24)(25,26,31,33)(27,34,28,29)(30,32,38,40)(35,39,36,37)(11,15)(12,19)(18,23)(20,24)(25,27,31,28)(26,29,33,34)(30,36,38,35)(32,39,40,37)(1,3,5,4)(2,6,8,7)(9,10)(11,12)(13,21)(14,17)(15,19)(16,22)(18,24)(20,23)(25,28,31,27)(26,29,33,34)(30,35,38,36)(32,39,40,37)(9,12)(10,15)(11,17)(13,20)(14,19)(16,23)(18,21)(22,24)(25,29)(26,27)(28,33)(30,37)(31,34)(32,35)(36,40)(38,39) involution — undirected(1,4,5,3)(2,7,8,6)(9,13)(10,16)(11,18)(12,20)(14,22)(15,23)(17,21)(19,24)(25,30,31,38)(26,32,33,40)(27,35,28,36)(29,37,34,39)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.