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