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