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