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