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