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