One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(6,9)(10,11)(17,25)(22,26)(23,28)(24,27) involution — undirected(1,2)(3,4)(13,14,18,19)(15,20,21,16)(17,22,25,26)(23,27,28,24)(5,6,8,9)(7,11,12,10)(14,19)(16,20)(22,26)(24,27)(5,7,8,12)(6,10,9,11)(13,15,18,21)(14,20,19,16)(17,23,25,28)(22,27,26,24)(13,16,18,20)(14,21,19,15)(17,24,25,27)(22,28,26,23)(13,17)(14,22)(15,23)(16,24)(18,25)(19,26)(20,27)(21,28) involution — undirectedA 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.