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