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