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