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